CRCA National Technical Committee Update
October 2023
The CRCA National Technical Committee (NTC) held its fall meeting on October 25, 2023, in Montreal. The NTC brings together roofing contractors, provincial affiliate technical representatives, and manufacturers to share their expertise and discuss developments and issues in the roofing industry.
The key highlights from this meeting were as follows:
Moisture in roofing materials
CRCA has received numerous reports of ongoing issues with moisture in different roofing materials. Preliminary research indicates that there is little scientific evidence of the acceptable moisture levels for various roofing materials. The NRC presented preliminary methodology that could be completed to measure moisture levels and determine acceptable levels in terms of wind uplift, thermal, and material performance.
CSA A123.23
CSA A123.23 Product specification for polymer-modified bitumen sheet, prefabricated and reinforced was issued in 2015 as a replacement to CGSB 37-GP-56 and is the minimum requirements for prefabricated and reinforced polymer-modified bitumen sheets. The new standard is referenced in the 2020 National Building Code and as the 2020 model is adopted in provinces and territories, these materials must comply with the requirements of the new standard.
Wind Uplift
CRCA members have raised concerns related to how CSA A123.21 Standard test method of the dynamic wind uplift resistance of membrane-roof systems is applied to construction projects. Designers are inconsistent with the use and specification of this standard. Some designers are including the roof wind loads in the tender documents and drawings; however, others are delegating the work of calculating the roof wind loads to the roofing contractor. The requirements and calculation of wind loads are referenced in Part 4 Structural in NBC and should be completed by a “qualified professional”. Roofing contractors are better served when loading is determined prior to the tender stage so that the correct system is priced into their bid. The NTC passed a motion to support the CRCA wind uplift policy statement that will be presented to the board on November 2, 2023.
The NTC will continue to stay informed on the technical developments and ongoing research in the roofing industry and provide timely updates to CRCA members.
I encourage you to reach out to CRCA technical staff, Wendy Fraser or Troy Ferreira, if you have any questions or require further information.
Regards,
Stéphane Poissant
NTC Chair
The key highlights from this meeting were as follows:
Moisture in roofing materials
CRCA has received numerous reports of ongoing issues with moisture in different roofing materials. Preliminary research indicates that there is little scientific evidence of the acceptable moisture levels for various roofing materials. The NRC presented preliminary methodology that could be completed to measure moisture levels and determine acceptable levels in terms of wind uplift, thermal, and material performance.
CSA A123.23
CSA A123.23 Product specification for polymer-modified bitumen sheet, prefabricated and reinforced was issued in 2015 as a replacement to CGSB 37-GP-56 and is the minimum requirements for prefabricated and reinforced polymer-modified bitumen sheets. The new standard is referenced in the 2020 National Building Code and as the 2020 model is adopted in provinces and territories, these materials must comply with the requirements of the new standard.
Wind Uplift
CRCA members have raised concerns related to how CSA A123.21 Standard test method of the dynamic wind uplift resistance of membrane-roof systems is applied to construction projects. Designers are inconsistent with the use and specification of this standard. Some designers are including the roof wind loads in the tender documents and drawings; however, others are delegating the work of calculating the roof wind loads to the roofing contractor. The requirements and calculation of wind loads are referenced in Part 4 Structural in NBC and should be completed by a “qualified professional”. Roofing contractors are better served when loading is determined prior to the tender stage so that the correct system is priced into their bid. The NTC passed a motion to support the CRCA wind uplift policy statement that will be presented to the board on November 2, 2023.
The NTC will continue to stay informed on the technical developments and ongoing research in the roofing industry and provide timely updates to CRCA members.
I encourage you to reach out to CRCA technical staff, Wendy Fraser or Troy Ferreira, if you have any questions or require further information.
Regards,
Stéphane Poissant
NTC Chair